A data storage position management main program collects volume physical
storage position management information and physical storage apparatus
operation information from a storage apparatus, and stores them as
storage apparatus arrangement information and storage apparatus operation
information. The program also collects necessary information from schema
information in a DBMS, stores it as DBMS schema information, collects
mapping information in a host and virtual volume information in a virtual
volume switch, stores them as data storage position management
information, acquires execution history information from the host, and
stores it as a DBMS execution history information. The program determines
a data relocation plan having a better performance characteristic on the
basis of the above information.